Over 3.5 million cases of suspected child maltreatment were reported to state child protective service systems in 2006, with over 900,000 confirmed cases of maltreatment. The most common form of child maltreatment in the U. S. is neglect, accounting for over 64% of substantiated cases of child maltreatment (U. S. DHHS, 2008). Most neglect cases are served by in-home family preservation/family reunification (FP/FR) service systems that are mandated by federal policy and are a staple of child welfare services. Many FP/FR services-as-usual are based on a loose social support and case management model, and the effectiveness of these services for reducing future neglect has been poor in rigorous evaluations. More effective models with stronger scientific support, such as the SafeCare(R) (SC) model, are beginning to have broader dissemination and implementation in FP/FR service systems. Our work has shown that a number of adaptations to SC may be made by systems, organizations, and/or service providers in the implementation process. This proposed study addresses two implementation concerns, 1) the tension between adaptation and fidelity, and 2) improving fidelity assessment. The degree to which core elements of SC can be maintained while allowing for local adaptation is unclear and this concern is reflected in both prevention and intervention literatures. We have developed an approach to adaptation based on the collective research and experience of the investigative team that accounts for the dynamic nature of services in child-welfare settings. We call this the "Dynamic Adaptation Process" (DAP) because it uses data to prepare systems, organizations, and service staff to make appropriate decisions about adaption during service delivery and provides checks and balances in the adaptation process. The DAP involves identifying core elements and adaptable characteristics of an EBP, then supporting implementation with specific training on allowable adaptations to the model, and fidelity monitoring and support. Subsequent In-vivo coaching then supports appropriate adaptations to the EBP. We propose this as a general model to be tested in a large scale SC implementation in California. The proposed project will examine the feasibility, acceptability, and utility of the DAP and test the degree to which fidelity can be maintained in implementation as usual (IAU) compared to DAP implementation. We will also examine provider and client satisfaction with services delivered under the two implementation approaches. 7. Project Narrative Child neglect is the most prevalent form of child maltreatment in the United States but there are few evidence- based practices to address this serious problem. In this study, SafeCare(R), a rigorously tested, implementation ready evidence-base practice will be implemented as usual compared to using a "Dynamic Adaptation Process" that facilitates a planned approach that is based on assessments of system, organization, provider, and client characteristics. The proposed study will assess the feasibility, acceptability, and utility of the using the DAP to implement SafeCare compared to implementation as usual, and will also assess fidelity and provider and client outcomes in the two conditions.